negative

Why the absolute value of the max negative integer -2147483648 is still -2147483648?

匿名 (未验证) 提交于 2019-12-03 00:48:01
可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效,请关闭广告屏蔽插件后再试): 由 翻译 强力驱动 问题: The result of abs(-2147483648) is -2147483648, isn't it? it seems unacceptable. printf ( "abs(-2147483648): %d\n" , abs (- 2147483648 )); output: abs (- 2147483648 ): - 2147483648 回答1: The standard says about abs() : The abs , labs , and llabs functions compute the absolute value of an integer j . If the result cannot be represented, the behavior is undefined. And the result indeed cannot be represented because the 2's complement representation of signed integers isn't symmetric. Think about it... If you have 32 bits in an int ,

Are there binary literals in Java?

匿名 (未验证) 提交于 2019-12-03 00:46:02
可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效,请关闭广告屏蔽插件后再试): 问题: I want to declare my integer number by a binary literal. Is it possible in Java? 回答1: Look at this link: http://en.wikibooks.org/wiki/Java_Programming/Literals/Numeric_Literals/Integer_Literals In Java, you may enter integer numbers in several formats: 1) As decimal numbers such as 1995, 51966. Negative decimal numbers such as -42 are actually expressions consisting of the integer literal with the unary negation operation. 2) As octal numbers, using a leading 0 (zero) digit and one or more additional octal digits (digits between 0 and 7),

triplets 、triplet Loss和 hard triplets

匿名 (未验证) 提交于 2019-12-03 00:30:01
本文大多数知识来源于此文:https://blog.csdn.net/fire_light_/article/details/79592804 triplets 设左一的图为 Anchor(参考点),左二为 Negative(反例),右一为 Positive(正例),这三张图片构成一个三元组(t riplet ),其中 A和P的欧式距离可能很大,A和N的欧式距离可能很小。 triplet Loss 什么是Triplet Loss呢?顾名思义,也就是根据三张图片组成的三元组(Triplet)计算而来的损失(Loss)。 其中,三元组由Anchor(A),Negative(N),Positive(P)组成,任意一张图片都可以作为一个基点(A),然后与它属于同一人的图片就是它的P,与它属于同一人的图片就是它的N。 Triplet Loss 的学习目标可以形象的表示如下图: 网络没经过学习之前,A和P的欧式距离可能很大,A和N的欧式距离可能很小,如上图左边,在网络的学习过程中,A和P的欧式距离会逐渐减小,而A和N的距离会逐渐拉大。 也就是说,网络会直接学习特征间的可分性:同一类的特征之间的距离要尽可能的小,而不同类之间的特征距离要尽可能的大。 意思就是说通过学习,使得类间的距离要大于类内的距离。 损失函数 为: 其中,左边的二范数表示类内距离,右边的二范数表示类间距离,α是一个常量

分类问题的几个评价指标

匿名 (未验证) 提交于 2019-12-03 00:21:02
转自 https://blog.csdn.net/simplelovecs/article/details/50520602 1. 四个概念定义:TP、FP、TN、FN 先看四个概念定义: - TP,True Positive - FP,False Positive - TN,True Negative - FN,False Negative 如何理解记忆这四个概念定义呢? 举个简单的二元分类问题 例子: 假设,我们要对某一封邮件做出一个判定,判定这封邮件是垃圾邮件、还是这封邮件不是垃圾邮件? 如果判定是垃圾邮件,那就是做出(Positive)的判定; 如果判定不是垃圾邮件,那就做出(Negative)的判定。 True Positive(TP)意思表示做出Positive的判定,而且判定是正确的。因此,TP的数值表示正确的Positive判定的个数。 同理,False Positive(TP)数值表示错误的Positive判定的个数。 依此,True Negative(TN)数值表示正确的Negative判定个数。 False Negative(FN)数值表示错误的Negative判定个数。 2. Precision、Recall、Accuracy、F1 Score(F Score) 四个概念定义: precision = TP / (TP + FP) recall = TP /

Django报错:AssertionError: Negative indexing is not supported.

杀马特。学长 韩版系。学妹 提交于 2019-12-02 05:38:50
AssertionError: Negative indexing is not supported. 它是不支持负索引的意思。 报该错误时,你需要在你的视图或其他地方,或查看报错日志,检查索引是否为负。 如下图,若改成[3:] 就可运行,即使列表长度不足,也不会报错。 来源: https://blog.csdn.net/s_kangkang_A/article/details/102723287

Linsheng - Excellent Jump Starter With Reverse Polarity Protection

你离开我真会死。 提交于 2019-12-01 07:59:42
These are the batteries that are talking about, and the battery contains electrical energy. If handled improperly, it can be dangerous. There is always the risk of injury, damage to the battery or starter and fire. Portable jump starters have a variety of built-in safety features, which is a good thing. Short-circuit protection – prevents large currents from flowing from positive clamp to negative clamp when accidentally touching together Overcurrent protection – prevents damage to the actuator by preventing it from supplying current beyond the peak limit Overload protection – prevents the

【论文笔记】S3FD:Single Shot Scale-invariant Face Detection

◇◆丶佛笑我妖孽 提交于 2019-11-29 22:28:20
&论文概述 题目 :Single Shot Scale-invariant Face Detection 作者及单位 :Shifeng Zhang, Xiangyu Zhu, Zhen Lei, Hailin Shi, Xiaobo Wang, Stan Z. Li. CBSR & NLPR, Institute of Automation, Chinese Academy of Sciences, Beijing, China University of Chinese Academy of Sciences, Beijing, China 获取地址 : https://arxiv.org/abs/1708.05237 &总结与个人观点 S3FD是针对人脸检测提出的,通过解决基于anchor设计的检测方法的常见问题:当目标变小,检测器的性能急剧降低,设计了一个新颖的人脸检测器。提出了1)在更多层上提取anchor以及选取一系列合理的anchor尺度以解决人脸的不同尺度问题的尺度平衡网络;2)提高小人脸的召回率的尺度补偿anchor匹配策略;3)降低小人脸的false positive的背景标签的最大输出方法。 我认为这篇论文在人脸检测领域种很有创新,而且提出的解决方案都不难理解,值得一看。 &贡献 1) 提出scale-equitable的人脸监测框架来处理不同尺度的人脸

Notes of assignments in week 1

无人久伴 提交于 2019-11-29 00:33:20
Q1 本题要求编写程序,找出给定的 n个数中的最大值及其对应的最小下标(下标从0开始)。 输入格式: 输入在第一行中给出一个正整数 n( 1)。第二行输入 n个整数,用空格分开。 输出格式: 在一行中输出最大值及最大值的最小下标,中间用一个空格分开。 输入样例: 6 2 8 10 1 9 10 输出样例: 10 2 Notes: 1) Say that we declare a var "max" to store the max value of input on the second line. We CANNOT INIT the var with an initial value, say, 0, since the input on the second line may be positive int, 0 as well as negative int!!! If we init "max" with 0, and assume that all of the input are negative values, the output will be 0 rather than the max value in the negative input, since the init value of 'max' is 0, which is greater than

How do negative margins in CSS work and why is (margin-top:-5 != margin-bottom:5)?

烈酒焚心 提交于 2019-11-28 17:38:13
How do negative margins in CSS work and why is (margin-top:-5 != margin-bottom:5)? 解答 Negative margins are valid in css and understanding their (compliant) behaviour is mainly based on the box model and margin collapsing. While certain scenarios are more complex, a lot of common mistakes can be avoided after studying the spec. For instance, rendering of your sample code is guided by the css spec as described in calculating heights and margins for absolutely positioned non-replaced elements . If I were to make a graphical representation, I'd probably go with something like this (not to scale):

题解 CF1206B 【Make Product Equal One】

家住魔仙堡 提交于 2019-11-28 04:12:51
题目: CodeForces链接 Luogu链接 思路: 这是一个一眼题 我们不妨把所有的数都看做是 \(1\) (取相应的花费,如: \(6\) 的花费就是 \(6 - 1 = 5\) , 拿变量 \(ans\) 记录)。 如果这一个是负数,拿一个变量 \(negative\) 记录负数的数量。 对于负数,当有偶数个的时候,把他们都变成 \(-1\) 是无所谓的,因为偶数个 \(-1\) 相乘的最终答案是 \(1\) ,所以当有偶数个负数时答案为 \(ans - negative × 2\) (乘上 \(2\) ,) 最终答案是 \(ans - (negative - negative % 2)\) 来源: https://www.cnblogs.com/GJY-JURUO/p/11391495.html